The present invention relates to a prime mover power transmission device converting a reciprocating power input to a rotating output, at a constant average torque.
It is well known that a rotating mass, or gyroscope, tends to remain oriented in a plane perpendicular to its spin axis. When a force is applied to the gyroscope spin axis urging the spin axis to be displaced in a different direction, a precessional momentum or force is induced. If an oscillatory motion is applied to the gyroscope spin axis, the precessional momentum is also oscillatory and is exerted in a plane perpendicular to the spin axis, the oscillatory motion being maximum 90.degree. away from the point of application of the input oscillatory motion.
The present invention provides a constant torque rotating output for an oscillating crankless engine. A gyroscopic transmission, of the type disclosed in prior application Ser. No. 785,943 is disposed between the reciprocating member of the input crankless reciprocating engine and the rotatable output shaft. The transmission comprises a rotating mass or gyroscope which is caused to spin, for example, by way of an electric or fluid motor coupled to its hub shaft. The gyroscope spins relative to an enclosure or frame journally supporting the gyroscope shaft, the enclosure or frame being pivotably supported about an axis within a ring or gimbal. The gimbal is in turn pivotably supported, about an axis disposed at right angle with the axis supporting the gyroscope enclosure or frame, by a pair of support brackets depending from a support plate or base, on which are also mounted the reciprocating engine oscillating member and the rotatable output shaft. The power input consists of a rigid connecting link having an end pivotably connected to the gimbal at a point substantially on the axis around which the gyroscope enclosure or frame is free to pivot. The input connecting link is reciprocated by way of a prime mover consisting of the oscillating member, such as the free piston or free cylinder, of the reciprocating engine coupled to the other end of the connecting link. The output consists of one or a pair of connecting links each having an end pivotably connected to the gyroscope enclosure or frame at a point substantially 90.degree., in angular position, from the point of application of the input connecting link, i.e., in a plane substantially passing through the axis of pivoting of the gimbal.
When a deflection is applied to the gimbal, and consequently to the gyroscope enclosure or frame, by the input connecting link, the gyroscope enclosure or frame is precessionally displaced, and the reaction of the pivot bearing causes the gyroscope enclosure or frame to oscillate about its axis of pivoting and thus causes reciprocation of the output connecting links. The reciprocating motion of the output connecting links is transformed into a rotary motion of the output shaft, by means of one-way clutches provided with an eccentric crank pin to which the end of the connecting link is connected.
Crankless reciprocating engines of the internal combustion type, as well as of the external combustion type such as Stirling-type engines, have been known for quite some time. Crankless reciprocating engines of the internal combustion type may be of the spark ignition or of the compression ignition, or diesel, type. Such engines have a free piston which is reciprocated within the cylinder. One side of the free piston faces the combustion chamber and the other side acts as a compressor piston, for example for a built-in compressor disposed at the other end of the cylinder. The reciprocating motion of the piston opens appropriate inlet and outlet ports through the wall of the cylinder, the inlet ports admitting to the combustion chamber an appropriate air-fuel mixture in the ignition combustion type of engine, or an appropriate amount of air into which fuel is injected at the end of the compression stroke of the piston in compression ignition engines. During combustion of the fuel-air mixture, the piston is propelled in the direction compressing air in the compressor portion of the cylinder, the outlet port is open, thus permitting the combustion residual gases to exhaust, and the piston is returned towards the combustion chamber through its compression stroke by the air pressure remaining in the compressor chamber. In view of the difficulty in transforming the reciprocating motion of the piston into, for example, a rotating motion, the exhaust gases from the engine drive an outlet gas turbine, for example, which provides such rotary motion by driving, generally through a gear reduction drive, an output shaft while the air compressed in the compressor is used for scavenging and sometime supercharging the engine combustion chamber.
In Stirling-type engines, the power for reciprocating the piston, instead of being obtained as a result of igniting a fuel-air mixture drawn into the combustion chamber is obtained from the rapid expansion of a fluid, generally a gas, situated in an expansion space in the cylinder. Heat is applied to the walls of the cylinder expansion space from the outside by way of a gas burner, concentrated solar heat, or the like. A displacer piston moves the hot gas from the hot expansion space through a regenerator to a cooling space, and the cooled gas is returned by the displacer piston to the expansion space through the regenerator in which it is pre-heated. In modern Stirling-type engines, helium is often used as the working gas, and the piston works against a bounce gas, such as air, contained in a chamber in the cylinder opposite to the expansion space or chamber, which acts to cushion the piston reversal and to push the piston to reduce the volume of the expansion space prior to expansion of the hot gas. Often, air is introduced and exhausted from the bounce gas chamber by means of appropriate poppet valves or reed valves, such that the bounce gas chamber acts as a source of compressed air. Applications have been made of Stirling engines, using for example solar heat energy as the source of heat, to provide electricity, by placing a magnet in the mass of the engine piston and disposing in the cylinder wall an appropriate stator winding in which electric power is generated.
Only indirect means have heretofore been proposed for converting the energy developed by a crankless reciprocating engine, such as for example utilizing the exhaust gases for running a gas turbine, using the reciprocation of the piston to compress air or a gas, to pump a fluid, gas or liquid, or to generate electricity. Direct conversion of the reciprocating motion of the piston into the more familiar rotating motion of a shaft can be accomplished only by a conventional connecting rod-crankshaft transmission mechanism, the connecting rod being conventionally attached at one end to the piston, thus converting the crankless engine into a conventional crankshaft engine, and destroying the simplicity of structure and operation of crankless reciprocating engines.
As there is no mechanical connection between the piston and the cylinder in crankless engines, if the piston is made relatively massive, that is with a high inertia, and the cylinder relatively light, that is with a low inertia, the cylinder is caused to oscillate relative to the piston rather than the piston relative to the cylinder. The present invention is addressed to a mechanical arrangement for converting the reciprocating motion of a crankless reciprocating engine, preferably of the reciprocating cylinder type, to a rotation motion of an output shaft by means of a gyroscopic transmission, the oscillating cylinder being slidably supported by way of a stationary sleeve or by means of appropriate linear guiding ways relative to a stationary frame or platform or, alternatively, being spring mounted such as to be free to oscillate during the reciprocation of the piston.
Attempts have been made in the past to couple the oscillating cylinder of free-piston engines to a crankshaft. Because oscillating cylinder engines have their own natural operating frequency and seek their own stroke length, they are not compatible with direct coupling to a crankshaft through a connecting rod, and it has been observed that oscillating cylinder engines run a crankshaft in one direction, and then suddently begin running the crankshaft in an opposite direction. It has been further observed that oscillating cylinder engines run very poorly in either direction.
A further problem associated with oscillating cylinder engines as a result of the cylinder oscillating at its own natural resonant frequency is that load variations at their output do not alter the frequency noticeably, but they do alter the stroke amplitude, which is incompatible with a rod and crankshaft mechanism for converting reciprocating motion to rotating motion. The gyroscopic transmission of the present invention permits to readily transform the variable amplitude reciprocation of an oscillating cylinder engine to a rotating motion at a substantially constant torque.